Bone fracture reduction device and methods for using same

ABSTRACT

A device and method for treating bone fractures/lesions using an inflatable body is provided. The inflatable body includes a balloon having a substantially flat horizontal surface for quick easy insertion into bone beneath the fracture so as to align misaligned fragments of the fracture and/or to collapsed bone. The body has a shape and size to compress at least a portion of the cancellous bone to form a cavity in the cancellous bone and/or to restore the original position of the outer cortical bone, if fractured or collapsed. The inflatable body has a stylet attached to its distal end so that once the inflatable body is deflated it can be twisted about the stylet to have a smaller profile so as to be easily withdrawn from the bone.

TECHNICAL FIELD

The present disclosure relates to inflatable devices for the treatmentof bone fractures.

BACKGROUND

Fractures, lesion and collapsing of bone structure can occur in humansdue to age, disease or trauma. There are many areas of bone that areprone to collapsing/depression, such as vertebra, proximal humerus,tibial plateau, distal radius and calcaneous. A bone tamp can be used torestore collapsed bone and re-align bone fragments caused by fracturesfollowed by injection of bone cement to fill any fractures, as well as,the void created after the inflated device is removed. Precisepositioning of the inflatable device beneath the deepest point of thedepression in the collapsed area or bone fragments is essential inproperly restoring the correct alignment of the bone fragments orreduction of the bone using a rounded inflatable device. If a roundinflatable device is improperly placed beneath the depression,misalignment of the fragments or under/over reduction can result. Timeand skill of the surgeon as well as limited work area to maneuver thedevice makes it difficult to always achieve proper placement. A betterinflatable body that facilitates proper placement in bone is needed.

SUMMARY

This application is directed to a bone reduction device and method fortreating fractures/lesions in bone. In particular, a bone reductiondevice is provided. The bone reduction device comprises a fill tubeextending along a longitudinal axis having a proximal end, a distal end,and a lumen extending from the proximal end to the oppositely disposeddistal end along the longitudinal axis. An inflatable body having a wallconfigured to define a fillable cavity is attached to the distal end ofthe fill tube and the fillable cavity is in fluid communication with thelumen of the fill tube. The inflatable body is configured to have ahorizontal surface when inflated. The device also has a styletpositioned within the lumen of the fill tube and may or may not beattached to the distal end of the inflatable body. It is contemplatedthat the distal end of the fill tube, the distal end of the stylet orboth can be attached so that when the fill tube and/or the stylet istwisted, the deflated inflatable body wraps around the fill tube so asto reduce it's profile for easy removal. The device further comprises aninner restraining member continuously connected to an inner surface ofthe wall of the inflatable body along the longitudinal axis so as todirectionally restrain expansion of the inflatable body so as to definea substantially flat horizontal surface. The device is configured forinsertion through a cannula into a bone adjacent a fracture so that itcan be used to realign bone fragments misaligned due to a bone fractureand/or re-establishes height to a collapsed part of the bone.

In one embodiment, according to the principles of the disclosure, amethod for treating fractures and collapsed bone is provided. The methoduses a bone reduction device comprising a fill tube extending along alongitudinal axis having a proximal end, a distal end, and a lumenextending from the proximal end to the oppositely disposed distal endalong the longitudinal axis. An inflatable body having a wall configuredto define a fillable cavity attached to the distal end of the fill tubewherein the fillable cavity is in fluid communication with the lumen ofthe fill tube and a portion of the wall is made from a material having ahigher durometer than the rest of the wall is provided. A portion of theinflatable body wall having a higher durometer reading causing it toinflate less than the rest of the inflatable body so as to form asubstantially flat horizontal surface when inflated. The horizontalsurface can be coated with radio-opaque or fluorescent material that isdetectable by medical imaging devices so as to determine orientation ofthe horizontal surface when placed in the bone. This allows a user ofthe device, for example a surgeon, to make sure that the horizontalsurface is properly positioned beneath the deepest point in thedepression so that when inflated, the inflatable body provides an evenand consistent pressure to the bone so as to result in proper repair ofthe collapsed area.

The device also has a stylet having first and second flattened portions,which is positioned within the lumen of the fill tube so that thedistance between the first and second flattened portions define thelength of the substantial flat horizontal surface. In one embodiment ofthe present disclosure, the stylet is attached to the distal end of theinflatable body so that when the stylet is rotated either in theclockwise or counter clockwise direction, the deflated inflatable bodytwists about the stylet so as to reduce the profile of the inflatablebody for removal. Either the proximal and distal flattened portions ofthe stylet and/or the substantially flat horizontal surface is coatedwith a radio-opaque or fluorescent coating so as to indicate locationand orientation of the flat surface. The device is configured forinsertion through a cannula into the bone adjacent the fracture and/orbeneath the collapsed bone.

A method for treating a bone fracture comprising preparing bone forreceiving the device of the present disclosure is provided. Insertingthe device into the bone wherein the inflatable body is in a deflatedstate. Once inserted, orientating the horizontal surface of theinflatable body below a fracture or collapsed portion of bone to betreated. Once oriented properly, inflating the inflatable body by addingfill material, for example saline or contrast, so that the horizontalsurface compacts calcaneous bone and/or bone marrow to create a void andto aid in establishing zero malreduction of the bone. Once the properreduction is established, the inflatable body is deflated and optionallytwisted about the stylet located within the lumen and attached to thedistal end so as to reduce the profile of the deflated inflatable bodyfor easy removal from the bone. Removing the catheter from the bone.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more readily apparent from thespecific description accompanied by the following drawings, in which:

FIG. 1 is a perspective view of one particular embodiment of a bonefracture reduction device in accordance with the principles of thepresent disclosure;

FIG. 1A is a cross section between the arrows indicated in FIG. 1;

FIG. 2 a top view of a stylet as shown in FIGS. 1 and 1A constructed inaccordance with the teachings of the present invention;

FIG. 3 is another perspective view of the bone fracture reduction devicewith the deflated inflatable body twisted about the distal end inaccordance with the principles of the present disclosure of FIG. 1;

FIG. 4 is a perspective view of the bone fracture reduction device foruse in a long bone such as the tibial plateau, constructed in accordancewith the teachings of the present invention;

FIG. 5 is an anterior/posterior view of the bone fracture reductiondevice for use in a long bone such as the tibial plateau, constructed inaccordance with the teachings of the present invention of FIG. 4; and

FIG. 6-FIG. 12 are cross sectional views of various shapes of theinflatable body of the bone fracture reduction device in accordance withthe teachings of the present invention; and

Like reference numerals indicate similar parts throughout the figures.

DETAILED DESCRIPTION

A device and method is described for treating bone fractures and/or bonecollapse. For illustrative purposes, the apparatus and method shall bedescribed in the context of treating fractures and restoring properreduction of a collapsed portion of a bone.

The present disclosure may be understood more readily by reference tothe following detailed description of the disclosure taken in connectionwith the accompanying drawing figures, which form a part of thisdisclosure. It is to be understood that this disclosure is not limitedto the specific devices, methods, conditions or parameters describedand/or shown herein, and that the terminology used herein is for thepurpose of describing particular embodiments by way of example only andis not intended to be limiting of the claimed disclosure. Also, as usedin the specification and including the appended claims, the singularforms “a,” “an,” and “the” include the plural, and reference to aparticular numerical value includes at least that particular value,unless the context clearly dictates otherwise. Ranges may be expressedherein as from “about” or “approximately” one particular value and/or to“about” or “approximately” another particular value. When such a rangeis expressed, another embodiment includes from the one particular valueand/or to the other particular value. Similarly, when values areexpressed as approximations, by use of the antecedent “about,” it willbe understood that the particular value forms another embodiment. It isalso understood that all spatial references, such as, for example,horizontal, vertical, top, upper, lower, bottom, left and right, distaland proximal, are for illustrative purposes only and can be variedwithin the scope of the disclosure. For example, the references “upper”and “lower” are relative and used only in the context to the other, andare not necessarily “superior” and “inferior”.

Further, as used in the specification and including the appended claims,“treating” or “treatment” of a disease or condition refers to performinga procedure that may include administering one or more drugs to apatient (human, normal or otherwise or other mammal), in an effort toalleviate signs or symptoms of the disease or condition. Alleviation canoccur prior to signs or symptoms of the disease or condition appearing,as well as after their appearance. Thus, treating or treatment includespreventing or prevention of disease or undesirable condition (e.g.,preventing the disease from occurring in a patient, who may bepredisposed to the disease but has not yet been diagnosed as having it).In addition, treating or treatment does not require complete alleviationof signs or symptoms, does not require a cure, and specifically includesprocedures that have only a marginal effect on the patient. Treatmentcan include inhibiting the disease, e.g., arresting its development, orrelieving the disease, e.g., causing regression of the disease. Forexample, treatment can include reducing acute or chronic inflammation;alleviating pain and mitigating and inducing re-growth of new ligamentand/or bone, repairing a fracture or break in bone and other tissues; asan adjunct in surgery; and/or any repair procedure. Also, as used in thespecification and including the appended claims, the term “tissue”includes soft tissue, ligaments, tendons, cartilage and/or bone unlessspecifically referred to otherwise.

The term “reduction” as used in this application refers to a medicalprocedure to restore a fracture or dislocation to the correct alignment.When a bone fractures, the fragments lose their alignment in the form ofdisplacement or angulation. For the fractured bone to heal without anydeformity the bony fragments must be re-aligned to their normalanatonical position. Orthopedic surgeons attempt to recreate the normalanatomy of the fractured bone by reduction.

The following discussion includes a description of a device for treatingbone lesions, fractures and/or collapsed bone and related methods ofemploying the device in accordance with the principles of the presentdisclosure. Alternate embodiments are also disclosed. Reference will nowbe made in detail to the exemplary embodiments of the presentdisclosure, which are illustrated in the accompanying figures. Turningnow to FIGS. 1-12, there are illustrated components of the device fortreating bone lesions, fractures and/or collapsed bone in accordancewith the principles of the present disclosure.

The term “Touhy Borst” or “Y Tube” as used in the application refers toan adapter used for attaching catheters to various other devices.

The components of the bone reduction device can be fabricated frombiologically acceptable materials suitable for medical apparatuses,including metals, synthetic polymers, ceramics, thermoplastic andpolymeric material and/or their composites. For example, the componentsof the bone reduction device, individually or collectively, can befabricated from materials such as stainless steel alloys, commerciallypure titanium, titanium alloys, Grade 5 titanium, super-elastic titaniumalloys, cobalt-chrome alloys, stainless steel alloys, superelasticmetallic alloys (e.g., Nitinol, super elasto-plastic metals, such as GUMMETAL® manufactured by Toyota Material Incorporated of Japan, Fe—Mn—Siand Fe—Ni—Co—Ti composites), ceramics and composites thereof such ascalcium phosphate (e.g., SKELITE™ manufactured by Biologix Inc.),thermoplastics such as polyaryletherketone (PAEK) includingpolyetheretherketone (PEEK), polyetherketoneketone (PEKK) andpolyetherketone (PEK), carbon-PEEK composites, PEEK-BaSO₄ polymericrubbers, polyethylene terephthalate (PET), fabric, silicone,polyurethane, silicone-polyurethane copolymers based materials,polymeric rubbers, polyolefin rubbers, semi-rigid and rigid materials,thermoplastic elastomers, thermoset elastomers, elastomeric composites,rigid polymers including polyphenylene, polyamide, polyimide,polyetherimide, polyethylene, epoxy, and composites of metals andcalcium-based ceramics, composites of PEEK and calcium based ceramics,and combinations of the above materials. Various components of theanchoring bone reduction device may have material composites, includingthe above materials, to achieve various desired characteristics such asstrength, rigidity, elasticity, compliance, and biomechanicalperformance, durability and to provide a non-stick surface. Thecomponents of the bone reduction device may be monolithically formed,extruded, coextruded, hot molded, cold molded, press molded, integrallyconnected or include fastening elements and/or coupling components, asdescribed herein. In particular, the inflatable portion of the deviceaccording to the present disclosure can comprise flexible material,including (but not limited to) non-elastic materials such as PET, Mylaror Kevlar®, elastic materials such as polyurethane, latex or rubber,semi-elastic materials such as silicone, or other materials.

Since the inflatable body expands and comes in contact with cancellousbone, the materials used and thickness must have significant resistanceso as to resist surface abrasion, puncture and/or tensile stresses. Forexample, structures incorporating elastomer materials, e.g.,polyurethane, which have been preformed to a desired shape, e.g., byexposure to heat and pressure, can undergo controlled expansion andfurther distention in cancellous bone, without failure, while exhibitingresistance to surface abrasion and puncture when contacting cancellousbone. The present invention further discloses inflatable devices thathave one or more biased directions of inflation. For example, inflatabledevices having reduced lateral growth may provide improved fracturereduction because such devices can exert a greater vertical force and/ordisplacement within the treated bone. Such inflatable devices may alsoprotect the lateral and anterior/posterior sidewalls of bone, forexample long bone and vertebral body, by minimizing expansion towardsthese sidewalls and directing expansion to a greater degree along thelongitudinal axis of the bone. In situations where a surgical procedureis terminated when the inflatable device contacts a lateral corticalwall of the targeted bone, such biased expansion could permit improvedfracture reduction prior to reaching this procedure endpoint.

In one embodiment, as shown in FIGS. 1-3, the reduction device 05, inaccordance with the present disclosure, comprises a body 15 having alongitudinal axis “L” attached to a fill tube 17. The fill tube 17extends from body 15 to the distal end 40 of device 05. The device 05includes a lumen extending from the proximal end 28 of body 15 to theoppositely disposed distal end 40 of device 05 along the longitudinalaxis. This lumen extends through body 15, into fill tube 17 and iscontinuous with the fillable cavity 70 of inflatable body 50. Thefillable cavity 70 is defined by wall 60 and is configured to inflateupon receiving fluid material from fill tube 17. That is, fillablecavity 70 is attached to the distal end of the fill tube 17 and is influid communication with the lumen of the fill tube 17 so that fluidmaterial flowing from the fill tube 17 inflates inflatable body 50. Thefluid material used to inflate inflatable body 50 can be in the form ofa liquid or gas, for example, either saline or compressed air. Wheninflated, wall 60 of inflatable body 50 has a first wall portion 55 thatdefines a substantially flat horizontal surface that is configured toengage bone and provide force against bone fragments so as to realignthe fragments. In one embodiment in accordance with the presentdisclosure, inflatable body 50 has a second wall portion 65 that definesa second substantially flat horizontal surface configured to engagebone, as does the first wall portion 55. A Y tube 30 is attached forattaching surgical devices as required by the procedure.

FIG. 1A is a cross-section of the inflatable body 50 showing the flatstylet 25 at the dotted lines 90 and 95 shown in FIG. 1. In oneembodiment of the present disclosure, stylet 25 has a predominatelyround configuration with two flattened portions 80, 85 spaced apart fromone as shown in FIG. 1. Flat marker portions 80 and 85 are specificallypositioned on stylet 25, as shown in FIG. 2, so as to correspond to theproximal and distal boundaries of the substantially flat surfaces 55 and65 of the inflatable body. Flat marker portions 80 and 85 can be used toreplace gold and/or platinum marker bands often used as markers that notonly add greatly to the cost of the stylet but also require additionalmanufacturing steps to adhere the markers to the stylet 25. In addition,the gold/platinum markers can shift and therefore lead to imprecisereadings. Relying on imprecise readings can result in placement of thesubstantially flat surfaces 55 and 65 in a position that results inmisalignment or malreduction when inflated. The flat marker surfaces 80and 85 can be produced in the stylet 25 so that the flat surface of themarker is parallel with substantially flat surfaces 55 and 65 therebyproviding not only boundaries for the substantially flat surfaces 55 and65 but also provide information for proper orientation of inflatablebody 50. Therefore, locating flat marker surfaces 80 and 85 using amedical imaging or fluoroscope when device 05 is inserted into boneallows the surgeon to determine not only the positioning of thesubstantially flat surfaces 55 and 65 but also the orientation of thesesurfaces. This information allows for precise placement of theinflatable body 50, which often leads to better fracture repair.

Stylet 25 can have different shapes, such as, for example, round, oval,oblong, square, rectangular, polygonal, irregular, uniform, non-uniform,offset, staggered, tapered, consistent or variable, depending on therequirements of a particular application. In one embodiment inaccordance with the present disclosure, stylet 25 is round, for examplea stainless steel wire, and is configured to have a proximal flattenedportion 80 and a distal flattened portion 85. As shown in FIG. 1,proximal flattened portion 80 and a distal flattened portion 85 ofstylet 25 is positioned so as to define the proximal end ofsubstantially flat horizontal surfaces 55, 65 and the distal end ofsubstantially flat horizontal surfaces 55, 65. That is, the position ofportions 80 and 85 defines the length and location of the proximal anddistal ends of the substantially flat horizontal surfaces 55, 65, forexample the distance between 90 and 95 in FIG. 1. These flattenedportions 80 and 85 of stylet 25 can be marked, for example with aradio-opaque enhancer or fluorescent coating, so that detecting thesemarkers indicates the position, location and length of substantiallyflat horizontal surfaces 55, 65, so as to aid in the placement of theinflatable body 50 to assure proper alignment of fracture fragmentsreduction of collapsed bone.

As stated above, flattened portions 80 and 85 of stylet 25 eliminatesthe need for expensive platinum or gold markers/bands designed to markthe beginning and end of the substantially flat surface and provideinformation about the orientation of the horizontal surfaces 55, 65.This makes device 05 more economical to make and use. Stylet 25 of thepresent disclosure is easily and inexpensively manufactured by crimpinga stainless steel wire, to produce a round stylet having flattenedproximal and distal portions. Other materials and shapes for the styletare also contemplated. Once flattened portions 80, 85 are produced, theycan be coated with radio-opaque or fluoresce material for identificationduring placement.

FIG. 3 shows device 105 having stylet 125 extending through the lumen ofbody 115 to distal end 140. At distal end 140 stylet 125 is attached tothe distal end of the inflatable body 150 so that rotation of stylet 125in a clockwise or counter clockwise twists inflatable body 150 aboutstylet 125 so as to reduce its profile for existing out of bone.

FIG. 4 shows the device in operation in a long bone. An inflatable body250 having a substantially flat horizontal surface and stylet 245 isinflated in accordance with the present disclosure. As shown, the distalend 210 of long bone 205 is collapsed with the deepest point 215 havingfractures therein. The substantially flat horizontal surface ofinflatable body 250 is positioned beneath the deepest depression point215. As the inflatable body 250 is inflated in accordance with thepresent disclosure, it expands along path 220 so as to engage and applyforce to the deepest point 215 and surrounding area. As it is inflated,the substantially flat horizontal surface of inflatable body 250 pushesagainst the bone applying constant and equal pressure so as toreestablish the height of the collapsed bone along path 230. Expansionof the inflatable body 250 also aligns fragments of bone caused asresult of the fracture so as to facilitate proper healing of thefractured bone.

FIG. 5 shows the anterior/posterior view of the device 335 inserted intobone at point 390 in operation similar to FIG. 4. As with the embodimentshown in FIG. 4, an inflatable body 355 having a substantially flathorizontal surface 360 is positioned directly beneath the deepestdepression point 350 and is inflated in accordance with the presentdisclosure. In accordance with the teachings of the present disclosure,stylet 325 having flat portions (not shown) is used to properly positionthe substantially flat horizontal surface 360 beneath the deepestdepression point 350 of the collapsed bone so that when inflated, theinflatable body displaces along path 345 and presses against the deepestdepression point 350 of the bone applying constant and equal pressure soas to reestablish the height of the collapsed bone. Expansion of theinflatable body 355 aligns fragments of bone caused as result of thefracture so as to facilitate proper healing of the fractured bone.

In realigning bone fragments of a fracture and/or re-establishing heightto a collapsed bone, proper placement of the inflatable body 355 isessential. That is, to realign and correct collapsed bone, placing thesubstantially flat portion of the inflatable body 355 properly beneaththe fracture or collapsed area is essential for a favorable outcome ofthe treatment. The substantially flat horizontal surface of the deviceallows for easy placement under the fracture and/or collapsed area ofthe bone so that upon inflation of the fragments are realigned and/orcollapsed bone is corrected. In contrast, round or spherical shapedballoons are more difficult to properly place in situ due to thecurvature of the balloon. If not positioned below the deepest point ofthe depression, once expanded the round portion of the inflatable bodyonly partially restores the height of the collapsed bone. That is, thepoint directly under the outermost point of the round balloon is advancehigher than the rest of the balloon therefore leading to incompletecorrection of collapsed bone and/or misalignment of the bone fragments.Thus, the inflatable body of the present disclosure, having flatsurfaces parallel to the flat portions of the stylet, allows for properplacement of the inflatable body prior to expansion. Proper placement isessential in treating fractures and collapsed bones, for example inextremities of a human. Accordingly, a stylet having flattened portionsthat define the boundaries of the substantially flat surfaces as well asthe orientation of the surfaces allows a surgeon to place the inflatablebody properly in situ therefore making it easier and less time consumingto achieve proper placement of the inflatable body prior to inflation.This ultimately leads to a better outcome and less time in surgery for apatient.

FIG. 5-FIG. 12 show different configurations of the inflatable body inaccordance with the features and operations of the present disclosure.FIG. 6 is a cross section across the inflatable body 400 of the presentdisclosure at the flattened portion of the stylet 415. The outer wall ofthe inflatable body 400 includes a wall having a first portion 410 madeof material having a higher durometer, therefore less elastic than asecond portion 405 having a lower durometer. The second portion 405 ofthe wall having a lower durometer reading than the first portion 410.The wall can extend into the fillable cavity 425 along a longitudinalaxis of the wall and attached to an inner surface of the wall, like abridge, beneath the substantially flat horizontal surface of theinflatable body. This bridge section 420 extends from one side of theinflatable body to the other and prevents the inflatable body from fullyexpanding so as to establish the substantially flat horizontal surfaceof the inflatable body. This section can be made form material having ahigher durometer than the rest of the wall and therefore will not expandas much as the wall section having a lower durometer so as to producethe configuration shown in FIG. 6. The outer surface of first portion410 can contain ink, radio-opaque markings or fluorescence materials sothat this section can be tracked when positioning the inflatable body insitu.

FIG. 7 is a cross section across the inflatable body 500 of the presentdisclosure at the flattened portion of the stylet 515. The outer wall ofthe inflatable body 500 includes a wall having a first portion 510 madeof material having a higher durometer than a second portion 505. Thesecond portion 505 of the wall having a lower durometer reading than thefirst portion 510. The wall can extend into the fillable cavity 525along a longitudinal axis of the wall and attached to an inner surfaceof the wall, like a bridge 520, beneath the substantially flathorizontal surface of the inflatable body. This bridge section 520extends from one side of the inflatable body to the other and preventsthe inflatable body from fully expanding so as to establish thesubstantially flat horizontal surface of the inflatable body. Thissection can be made form material having a lower durometer than the restof the wall and therefore will expand more than the wall section havinga higher durometer so as to produce the configuration shown in FIG. 7.The outer surface of first portion 510 can contain ink, radio-opaquemarkings or fluorescence materials so that this section can be trackedwhen positioning the inflatable body in situ.

Similar to FIG. 6, FIG. 8 is a cross section across the inflatable body600 of the present disclosure at the flattened portion of the stylet615. The outer wall of the inflatable body 600 includes a wall having afirst portion 610 having a higher durometer, therefore less elastic thana second portion 605 having a lower durometer. The second portion 605 ofthe wall having a lower durometer reading than the first portion 610.The wall can extend into the fillable cavity 625 along a longitudinalaxis of the wall and attached to an inner surface of the wall, like abridge 620, beneath the substantially flat horizontal surface of theinflatable body. This bridge section 620 extends from one side of theinflatable body to the other and prevents the inflatable body from fullyexpanding so as to establish the substantially flat horizontal surfaceof the inflatable body. Unlike the bridge section 420 in FIG. 6, thebridge 620 in FIG. 8, has a straight configuration wherein the bridgesection 420 in FIG. 6 bulges outwardly around stylet 415. This sectionis made from material having a higher durometer than the rest of thewall and therefore will expand less than the wall section having a lowerdurometer so as to produce the configuration shown in FIG. 8.

FIG. 9 is a cross section across the inflatable body 700 of the presentdisclosure at the flattened portion of the stylet 715. The outer wall ofthe inflatable body 700 includes a wall having a first portion 710 madeof material having a higher durometer than a second portion 705. Thesecond portion 705 of the wall having a lower durometer reading than thefirst portion 710. Unlike FIGS. 6-8, the inflatable member of FIG. 9 hasno bridge section and the stylet is disposed in the internal cavity 725to produce the configuration shown in FIG. 9.

FIG. 10 is a longitudinal cross section across the inflatable body 800of the present disclosure along the portion of the stylet 815. The outerwall of the inflatable body 800 formed from a wall having a firstportion 810 made of material having a higher durometer, therefore lesselastic than a second portion 805. The second portion 805 of the wallhaving a lower durometer reading than the first portion 810. UnlikeFIGS. 6-9, the inflatable member 800 of FIG. 10 has no bridge sectionand stylet 815 is disposed in the internal cavity 825 to produce atriangular, parachute shaped configuration as shown in FIG. 10. The tipof stylet 815 being attached to the distal end of the inflatable body800.

Similar to FIG. 10, FIG. 11 has a triangular shape. FIG. 11 shows across section across the inflatable body 900 of the present disclosureat the flattened portion of the stylet 915. The outer wall of theinflatable body 900 formed from a wall having a first portion 910 havinga higher durometer, therefore less elastic, than a second portion 905having a lower durometer. The second portion 905 of the wall having alower durometer reading than the first portion 910. The wall can extendinto the fillable cavity 925 along a longitudinal axis of the wall andattached to an inner surface of the wall, like a bridge 920, beneath thesubstantially flat horizontal surface of the inflatable body. Thisbridge section 920 extends from one side of the inflatable body to theother and prevents the inflatable body from fully expanding so as toestablish the substantially flat horizontal surface of the inflatablebody. Unlike the bridge section in FIGS. 6-9, bridge 920, has a portionthat has a higher durometer and a section having a lower durometer. Thelower durometer section can be positioned below the first section of thewall 910 wherein the higher durometer of the bridge is positioned at anapex of the triangular/wedged shaped inflatable body. The section madefrom material having a higher durometer will expand less than the restof the wall so as to produce the wedge shape configuration shown in FIG.11.

Similar to FIGS. 6-8, FIG. 12 is a cross section across the inflatablebody 1000 of the present disclosure at the flattened portion of thestylet 1015. The outer wall of the inflatable body 1000 formed from awall having a uniform durometer. The wall can extend into the fillablecavity 1025, or have attached to the inside surface of the wall one ormore restraining bridges 1020 that extend along a longitudinal axis ofthe wall beneath the substantially flat horizontal surface of theinflatable body. These bridge sections 1020 extend from one side of theinflatable body 1000 to the other and prevent the inflatable body fromfully expanding so as to establish the substantially flat horizontalsurface of the inflatable body. These bridge sections 1020 can be madefrom material having the same of different durometer reading or can bethe same or different thickness so as to produce the configuration shownin FIG. 12. The proximal end of the inflatable body in FIG. 12 isattached to a catheter so that it can be filled with filling material asdescribed herein.

As discussed above, spherical portions of the inflatable body may berestrained by using inelastic, semi-elastic, elastic and elastomericmaterials in the construction of the inflatable body, or may beadditionally restrained as described. The material of the inflatablebody can be a non-elastic material, such as polyethylene tetraphthalate(PET), nylon, Kevlar® or other medical inflatable body/balloonmaterials. It can also be made of semi-elastic materials, such assilicone, rubber, thermoplastic rubbers and elastomers or elasticmaterials such as latex or polyurethane, if appropriate restraints areincorporated. The restraints can be continuous or made of discreteelements of a flexible, inelastic high tensile strength material havingthe same or different durometer and thicknesses. The thickness of theinflatable body is typically in the range of 2/1000ths to 25/1000ths ofan inch, although other thicknesses that can withstand increasedpressures, such as 250-400 psi or greater, even up to 500, 1000 or 2000psi, may be used.

Since the inflatable body expands and comes in contact with cancellousbone, the materials used and thickness of the wall of the inflatablebody must have significant resistance so as to resist surface abrasion,puncture and/or tensile stresses. For example, structures incorporatingelastomer materials, e.g., polyurethane, which have been preformed to adesired shape, e.g., by exposure to heat and pressure, can undergocontrolled expansion and further distention in cancellous bone, withoutfailure, while exhibiting resistance to surface abrasion and puncturewhen contacting cancellous bone. The present invention further disclosesinflatable devices that have one or more biased directions of inflation.For example, inflatable devices having reduced lateral growth mayprovide improved fracture reduction because such devices can exert agreater vertical force and/or displacement within the treated bone. Suchinflatable devices may also protect the lateral and anterior/posteriorsidewalls of the vertebral body by minimizing expansion towards thesesidewalls and directing expansion to a greater degree along thelongitudinal axis of the spine. In situations where a surgical procedureis terminated when the inflatable device contacts a lateral corticalwall of the targeted bone, such biased expansion could permit improvedfracture reduction prior to reaching this procedure endpoint.

The present invention further discloses inflatable devices having biasedinflation along the longitudinal axis of the inflatable devices.Inflatable devices capable of biased inflation along their longitudinalaxes may provide improved fracture reduction as such devices can bepreferentially expanded towards areas of higher cancellous bone densityand/or away from areas of lower cancellous bone density. Similarly,inflatable devices capable of biased inflation along their longitudinalaxes can be preferentially expanded towards areas that resist expansionof the device and/or away from areas that promote expansion of thedevice.

Due to the nature of the injury, disease or other treatments, as well asthe health and age of the patient suffering from these injuries, it maybe preferable to treat a bone with the devices of this disclosure duringan open or semi-open surgical procedure. In addition, a goal of thesurgery may be to replace the diseased or injured bone with materials(such as bone fillers or certain drugs) which do not flow, and whichthus are not well suited for a more minimally invasive procedure.

In assembly and use, the bone reduction device described herein isemployed with a surgical procedure for treatment of a disorder affectinga section of bone, such as a fracture, for example in a vertebrae orextremity of a patient. In use, the bone reduction device wherein theinflatable body is initially deflated and, after the bone to be filledwith the inflatable body has been prepared to receive the inflatablebody (such as by punching, drilling or otherwise displacing a smallamount of the cancellous bone directly beyond the opening of thecannula), is advanced into the bone through a cannula. The inflatabledevice is oriented preferably in the bone such that the substantiallyflat horizontal surface is positioned beneath the fracture, using theflattened portions of the stylet and fluoroscope/medical imagingmaterial to effect orientation and placement in accordance with thedescription of the present disclosure. Once in place, filler material isdirected into the fillable cavity of the expandable cavity so as toexpand the inflatable cavity and exert pressure on the cortical bone torealign fragments of the fracture and/or elevate collapsed bone to itsproper height. (FIGS. 4-5). Where such fracture or collapse has notoccurred, such pressure would desirably compress the bone marrow and/orcancellous bone against the inner wall of the cortical bone, therebycompacting the bone marrow of the bone to be treated and to furtherenlarge the cavity in which the bone marrow is to be replaced by abiocompatible, flowable bone material, such as bone void filler/bonecement.

The inflatable body is inflated to compact the bone marrow and/orcancellous bone in the cavity and, after compaction of the bone marrowand/or cancellous bone, the inflatable body is deflated and removed fromthe cavity. Following compaction of the bone marrow, the inflatable bodyis deflated and the stylet twisted so as to coil the inflatable bodyabout the stylet and reduce the profile of the inflatable body prior toremoval. The lower profile makes it easier for the device to be pulledout of the cavity by applying a manual pulling force to the cathetertube.

It should be understood that the various embodiments of inflatable bodydisclosed herein are by no means limited in their utility to use in asingle treatment location within the body. Rather, while exemplarytreatment location, these embodiments can be utilized in variouslocations within the human body are provided; this disclosure should notbe so limited. For example, the device according to the presentdisclosure can be useful in treating a fractures in various other areaswithin the body, including but not limited to fractures and/or impendingfractures of the femur, the radius, the ulna, the tibia, the humerus, orthe spine. Similarly, the various other disclosed embodiments can beutilized throughout the body, with varying results depending upontreatment goals and/or the anatomy of the targeted bone.

It will be understood that various modifications may be made to theembodiments disclosed herein. Therefore, the above description shouldnot be construed as limiting, but merely as exemplification of thevarious embodiments. Those skilled in the art will envision othermodifications within the scope and spirit of the claims appended hereto.

1-10. (canceled)
 11. A method for treating a bone fracture comprising:preparing bone for receiving the device of claim 1; inserting the deviceinto the bone wherein the inflatable body is in a deflated state;orientating the horizontal surface of the inflatable body below afracture or collapsed portion of bone to be treated; inflating theinflatable body so that the horizontal surface compacts calcaneous boneand/or bone marrow to create a cavity and establish zero malreduction ofthe bone; deflating the inflatable body; and removing the deflatedinflatable body from the bone.
 12. A method for treating a bone fractureof claim 11 where the horizontal surface of the inflatable body iscoated with a radio-opaque material and the step of orienting thehorizontal surface of the inflatable body further comprises using amedical imaging device to orientate the horizontal surface of theinflatable body beneath a fracture or collapsed portion of the bone tobe treated.
 13. A method for treating a bone fracture of claim 11wherein the step of removing the deflated inflatable body from the bonefurther comprises rotating the stylet in a clockwise or counterclockwise direction in order to twist the deflated inflatable body aboutthe stylet and reduce the profile of the deflated inflatable body priorto removing it from the bone.
 14. A method for treating a bone fractureof claim 11 further comprising injecting a bone filing material into thecavity formed by the inflatable body once the inflatable body is removedso as to treat and/or maintain zero malreduction. 15-20. (canceled)